The present invention relates to tables, especially tables the top of which is adjustable in its elevational position, particularly drafting tables or boards or work tables, wherein the table top is supported by weight balancing devices exerting a force of at least substantially constant effect.
Gas springs are frequently used for weight balancing table tops which are adjustable in their elevation. The gas springs are provided with a discharge valve for the purpose of controlling the force exerted by the gas spring. However, if, for example, as a result of controlling the gas spring too much gas is released, it becomes necessary to demount the gas spring and to refill the gas spring to the desired pressure for the further use. Further, the supporting force of gas springs may become weaker with the lapse of time due to leakage. Besides, an increase of the supporting force of a gas spring always makes it necessary to change or demount the spring and to insert a new spring. Gas springs also have a relatively high friction of their own and cause disturbing friction noises when the table top is adjusted in its elevational position.
Other types of weight compensating systems such as tension or pressure springs are not suitable for use in connection with table tops adjustable in their elevational position, because such other devices do not exert a constant force throughout their adjustment range. Such a force is necessary to counteract the weight of the table top.